[5] They form a group of plants that can be erect shrubs, climbing, or trailing, with stems that are often armed with sharp prickles.

[6] Their flowers vary in size and shape and are usually large and showy, in colours ranging from white through pinks, reds, oranges and yellows.

Each hip comprises an outer fleshy layer, the hypanthium, which contains 5–160 "seeds" (technically dry single-seeded fruits called achenes) embedded in a matrix of fine, but stiff, hairs.

Some species such as Rosa rugosa and [R. pimpinellifolia have densely packed straight prickles, probably an adaptation to reduce browsing by animals, but also possibly an adaptation to trap wind-blown sand and so reduce erosion and protect their roots (both of these species grow naturally on coastal sand dunes).

Plant geneticist Zachary Lippman of Cold Spring Harbor Laboratory found that prickles are controlled by the LOG gene.

[16] This rapid evolution may reflect an adaptation to genome confliction resulting from frequent intra- and inter-species hybridization and switching environmental conditions of growth.

[16] The genus Rosa is composed of 140–180 species and divided into four subgenera:[17] Some birds, particularly finches, eat the seeds.

A few, mostly species roses are grown for attractive or scented foliage (such as Rosa glauca and R. rubiginosa), ornamental thorns (such as R. sericea) or for their showy fruit (such as R. moyesii).

[19] It is estimated that 30 to 35 thousand rose hybrids and cultivars have been bred and selected for garden use as flowering plants.

In the early 19th century the Empress Josephine of France patronized the development of rose breeding at her gardens at Malmaison.

Generally they are harvested and cut when in bud, and held in refrigerated conditions until ready for display at their point of sale.

Rose hips are high in vitamin C, are, after the removal of the irritant hairs, edible raw,[25] and occasionally are made into jam, jelly, marmalade, and soup, or brewed for tea.

[26] Rose water has a very distinctive flavour and is used in Middle Eastern, Persian, and South Asian cuisine—especially in sweets such as Turkish delight,[27] barfi, baklava, halva, gulab jamun, knafeh, and nougat.

In the Indian subcontinent, Rooh Afza, a concentrated squash made with roses, is popular, as are rose-flavoured frozen desserts such as ice cream and kulfi.

[28][29] The flower stems and young shoots are edible, as are the petals (sans the white or green bases).

Under the American Federal Food, Drug, and Cosmetic Act,[32] there are only certain Rosa species, varieties, and parts are listed as generally recognized as safe (GRAS).

[40][36] Book Eleven of the ancient Roman novel The Golden Ass by Apuleius contains a scene in which the goddess Isis, who is identified with Venus, instructs the main character, Lucius, who has been transformed into a donkey, to eat rose petals from a crown of roses worn by a priest as part of a religious procession in order to regain his humanity.

[37] French writer René Rapin invented a myth in which a beautiful Corinthian queen named Rhodanthe ("she with rose flowers") was besieged inside a temple of Artemis by three ardent suitors who wished to worship her as a goddess; the god Apollo then transformed her into a rosebush.

[37] Albrecht Dürer's painting The Feast of the Rosary (1506) depicts the Virgin Mary distributing garlands of roses to her devotees.

Other impressionists including Claude Monet, Paul Cézanne and Pierre-Auguste Renoir have paintings of roses among their works.

[45] In 1986 President Ronald Reagan signed legislation to make the rose[46] the floral emblem of the United States.